Random selection electrical combination locks



Se t. 23, 1969 c. e. DOUGLAS ETAL 3,468,143

RANDOM SELECTION ELECTRICAL COMBINATION LOCKS- Filed Oct. 20, 1967 5Sheets-Sheet l c. G. DOUGLAS ETAL 3,468,143

Sept. 23, 1969 RANDOM SELECTION ELECTRICAL COMBINATION LOCKS 5Sheets-Sheet 2 Filed Oct. 20, 1967 Se t. 23, 1969 c. s. DOUGLAS ETAL3,468,143

5 Sheets-Sheet 5 Ray)? Sept. 23, 1969 Q DOUGLAS ETAL 3,458,143

RANDOM SELECTION ELECTRICAL COMBINATION LOCKS Filed Oct. 20, 1967 5Sheets-Sheet 4,

Sept. 23, 1969 c. G. DOUGLAS E AL 3,468,143

RANDOM SELECTION ELECTRICAL COMBINATION LOCKS Filed Oct. 20, 1967 5Sheis-Sheet 5 3,468,143 RANDOM SELECTION ELECTRICAL COMBINATION LOCKSClifford G. Douglas, London, and George H. G. Guttridge, Hertford Heath,England, assignors, by mesne assignments, to Bambino ElectronicsLimited, London, England, a British company Filed Oct. 20, 1967, Ser.No. 676,830 Claims priority, application Great Britain, Oct. 21, 1966,47,139/ 66 Int. Cl. E0511 47/00, 49/00 US. Cl. 70-277 12 Claims ABSTRACTOF THE DISCLOSURE An electrical combination lock comprising at least onemanually operable member connectible by drive means to at least onedriven member and releasable therefrom for independent movement, andelectrical contacts associated with the manually operable member anddriven member so as to complete an electrical circuit when the twomembers are in predetermined relative positions, so that the drivenmember can be set to any desired position by setting the manuallyoperable member to the same position with the drive means engaged, thedrive means being then disengaged to allow the manually operable memberto be moved to another position leaving the setting stored in the drivenmember so that the circuit can be re-made by moving the manuallyoperable member back to the said set position.

This invention relates to electrical combination locks for use tocontrol access to strong rooms, safes or enclosed areas, or to preventunauthorized changing of the condition of an electrical circuit or otherinstallation.

It is the object of the invention to provide a selector device which iscapable of setting into the lock, at the time of locking, anyarbitrarily selected combination which is memorized thereby until asubsequent unlocking operation is performed, the arrangement being suchthat the combination memorized is not revealed in any way, byinspection, by feel or by sound.

According to the invention, a selector device for an electricalcombination lock comprises a manual control settable to any one of aplurality of positions, a driven member also movable to any one of aplurality of positions, electrical contacts associated with said manualcontrol and with said driven member, an electrical circuit completed bysaid contacts when the control and the driven member are inpredetermined relative positions, drive coupling means between saidcontrol and said driven member, engageable to provide simultaneousrotation of said driven member by said control, and means fordisengaging said drive coupling means to permit movement of said manualcontrol independently of said driven member.

Preferably an electrically controlled latch is provided to hold thedrive coupling means in the disengaged position, releasing means for thesaid latch being actuated by completion of the electrical circuit.

The invention will now be described with reference to the accompanyingdrawings, in which:

FIGURE 1 is a circuit diagram showing the essential electrical circuitof the selector device;

FIGURE 2 is a diagram showing one arrangement according to theinvention;

FIGURE 3 is a diagram showing another arrangement according to theinvention;

FIGURE 4 shows an arrangement of a selector device States Patent "iceaccording to the invention in association with a mechanical lock; and

FIGURE 5 is a circuit diagram of the arrangement shown in FIGURE 4.

Referring to FIGURE 1, a rotary switch A having a series of fixedcontacts wiped by a rotor contact 11 has each of the said fixed contacts10 coupled to one of a plurality of corresponding fixed contacts 12 of asecond rotary switch B having a rotor contact 13. The rotor of theswitch A, which constitutes a manual control, is rotated by means of amanual knob, not shown, and is associated with a dial, not shown,bearing letters or numbers so that a diiferent letter or number isindicated for each position of the switch. Separate coaxial spindles 14and 15 carry the rotors of the two switches A and B, the two spindlescarrying respectively identical gear wheels 16 and 17. A third gearwheel 18, capable of meshing simultaneously with both the gear wheels 16and 17, is rotatably carried by a pivoted support (not shown) so as tobe capable of swinging into and out of engagement with the gear wheels16 and 17. A spring 19 urges the said gear wheel 18 into engagement withthe gear wheels 16 and 17, and a latch 20, loaded by a spring 21, isprovided to hold the said gear wheel out of engagement with the gearwheels 16 and 17. A manual control lever 22 is attached to the pivotalsupport to enable the gear wheel 18 to be moved to its disengagedposition when required.

A source of electric current, shown as a battery 23, is arranged in anelectrical circuit including the switches A and B in series, a manuallyoperable switch 24, and a solenoid 2.5 which when energised, releasesthe latch 20. The solenoid 25, or an additional solenoid, actuates orcontrols the actuation of the device protected by the lock.

The switch 24 is normally open, and the solenoid 25 is thereforede-energised. As will be hereinafter explained, the gear wheel 18, whenthe lock has been released, is in engagement with the gear wheels 16 and17. To set the lock, the switch A is moved to any chosen position, theswitch B being driven to the same position by the gears 16, 17, 18. Thelever 22 is then operated to disengage the gear wheel 18 from the gearwheels 16 and 17, the latch engaging automatically to hold the gearwheel in the disengaged position. The switch A is then moved to anotherposition, and it will be apparent that a circuit through the solenoid25, to release the latch, can be completed only by returning the switchA to the position to which it was previously set, and closing the switch24, the switch B serving as a memory to retain the required setting.When the switch A is returned to the previously set postiion, and theswitch 24 is closed, the solenoid is energised to release the latch 20and allow the gear wheel 18 to re-engage with the gear wheels 17 and 18and actuate, or allow to be actuated, the device controlled by the lock.

An alarm device is preferably provided which is actuate-d if the switch24 is closed when the switches A and B are not in positions ofcoincidence, so that any attempt to release the lock without correctlysetting the switch A causes the alarm to be actuated.

Only a relatively small number of possible settings could be provided bya single pair of switches A and B, and in practice, two or more sets ofsuch switches will be provided, the electrical circuit including all thepairs of switches in series. An example of a selector device includingfour pairs of switches is shown in FIGURE 2, the

switch pairs being arranged in two groups of two each.

faces thereof and each pair of opposite contacts being connected one tothe other. The switch rotors 33, 34 of the respective switches comprisegear wheels rotatable about a fixed shaft 35 on which the stator 31 ismounted. The rotor 33 of the switch A of each pair is fixed to a drum 36projecting at one portion of its periphery through a slot in a coverplate 30 enclosing the switches, the edge of the drum bearing indicia,e.g. letters or figures each of which appears in the window when theswitch rotor contact engages a different one of the stator contacts. Thedrum is rotatable by applying a rotating force, e.g. by the operatorsfinger, to its projecting portion. A pivoted frame, not shown in thedrawing but lying in a plane substantially perpendicular to that ofFIGURE 2, and movable about a pivot parallel to the shaft 35, carriesthird gear wheels 37 to engage with the gear wheels 33 and 34 of bothswitch group 26 and 27, the frame being urged by a spring 38 in adirection to engage the gear wheels 37 simultaneously with the gearwheels 33 and 34 of both switch pairs. A push button 39, projectingthrough the cover plate 30, is provided to move the frame about itspivot end and disengage the gear wheels 37 from the gear wheels 33 and34. The switch group 28 and 29 is identical with the switch group 26,27, and includes similar gear wheels 37 associated with the two switchpairs, a separate push button 39 being provided to disengage the gearsof these switch pairs.

Two latches 41 are provided each of which serves to latch the gearwheels 37 of one switch group in the disengaged position, the latchesbeing urged to the engaged postiion by springs 42. A common solenoid 43acting on armatures 44 carried by rods 45 acts, when energised, torelease the latches 41.

The solenoid 43 is included in an electrical circuit which also includesa source of electric current, shown as a battery 46, a manual switch 47,and all the pairs of switches 26, 27, 2'8 and 29 in series. Thus theoperation of the manual switch 47 can complete the circuit only when theswitches A and B of each pair 26, 27, 28 and 29 are in correspondingpositions to each other.

The switch 47, when in the position to open the contacts in the circuitincluding the switch pairs 26, 27, 28 and 29 closes contacts in anauxiliary circuit controlling an alarm device shown diagrammatically at48 and including a separate current source 49, the alarm being of theknown type which is brought into action by the opening of its controlcircuit. There is also included in the said auxiliary circuit, inparallel with the switch 47. another switch 51, conveniently amagnetically operated reed switch, which is normally open but is closedby energisation of a solenoid 52 in the circuit including the switchpairs 26, 27, 28 and 29, so that if when the said switch 47 is moved toopen the auxiliary circuit, the switch pairs 26, 27 28 and 29 are all incorresponding positions, the alarm is not actuated.

Each of the push buttons 39, when actuated to disengage the associatedgear wheels 37 from the gear wheels 33 and 34 closes a pair ofelectrical contacts 53, the closing of these contacts taking place onlywhen the latches 41 have become operative. The closing of either pair ofthese contacts 53 completes an electrical circuit which, if the selectordevice is associated with a mechanical lock actuates a solenoid or otherelectro-magnetic device to hold a bolt or like member in the engagedposition or, if the selector device is assoicated with an electricalapparatus, initiates operation of the said apparatus. Thus the lockingor operation-initiating function can be performed when either one of theswitch groups has been set and the manual controls of the switches ofthat group can be moved from their set positions before the other groupof switches has been set, enabling each group to be set by a differentperson 'without either of the people involved knowing what setting hasbeen made of the other group of switches.

FIGURE 3 shows a modified mechanism for coupling together two switches Aand B for constituting a manual control and a driven memberrespectively. A panel is indicated at 54 behind which the switches aremounted coaxially, the rotor of the switch A, shown at 55, being mountedon a spindle 56 projecting through the panel and carrying an operatingknob 57. The rotor 58 of the switch B is keyed to a separate spindle 59,coaxial with the spindle 56, and also keyed to the spindle 59, so as tobe slidable thereon, is a disc 61 in which is formed a hole 62 offsetradially from the centre of the disc. Another disc 63 fixed on thespindle 56 carries a pin 64 offset from its centre by the same radialdistance as the hole 62. A spring 65 surrounding the spindle 59 urgesthe disc 61 toward the disc 63 so that, in one relative angular positionof the discs, the pin 64 can enter the hole 62, the discs and pin thusconstituting a clutch coupling the switch rotors together. An arm 66,axially located with respect to the disc 61 but relative to which thesaid disc is rotatable, cooperates with a push-button 67 mounted in apanel 54 so that, by pressing on the said push button, the arm 66 anddisc 61 can be moved axially away from the disc 63 to disengage the pin64 from the hole 62 and allow the switch rotor 55 to be rotatedindependently of the switch rotor 58. A pivoted latch 68 is provided aoengage the arm 66 when the latter is moved to disengage the clutch,engagement of the latch with the arm being effected by gravity or by aspring (not shown), and a solenoid 69 is provided to release the latch68. The solenoid is arranged in an electrical circuit corresponding tothat shown in FIGURE 1, so that the operation of the device is the sameas has already been described with reference to FIGURE 1.

Referring to FIGURE 4, a lock for a safe, strongroom or the likecomprises a bolt 71 mounted, for example, in a door a part of which isshown at 72, the bolt entering a recess 73 in a door jamb 74. The bolt71 is moved rectilinearly by a gear wheel 75 meshing with rack teeththereon. A door handle or knob (not shown) rotates a further gear wheel76 and also drives through a speed-multiplying gearing, an electricgenerator 77. An intermediate gear 78, capable of coupling the gears 75and 76 one to the other, is normally disengaged from both of them, butcan be drawn into a meshing position by energisation of a solenoid 79.

A selector device 81, corresponding to that shown in FIGURE 2, has thethird gear wheels of the gear trains coupling the manual controls to thedriven members mounted on the bolt 71, as shown at 82 so that when thebolt is engaged, as shown, the said third gear Wheels are in thedisengaged position and retraction of the bolt brings them to theengaged position.

A set of electrical contacts '83 controlled by a roller 84 which dropsinto a notch 85 in the bolt 71 to open the contacts when the bolt isengaged, are at other times held closed by engagement of the roller 84with a side surface of the bolt, and a second set of electrical contacts86, similarly controlled by a roller 87 are opened by the dropping ofthe roller 87 into a notch 88 when the third gear wheels 82 are in theposition to mesh with the other gears of the selector device, and bydropping of the roller 87 into a notch 89 when the bolt 71 is movedoutwardly beyond the last-mentioned position. A manually-operable switch91 is provided to short-circuit the contacts 86.

Referring now to FIGURE 5, the generator 77 feeds current to the commonpoint of two coils 92 and 93 in the solenoid 79, the two coils 92 and 93being connected in parallel, each through a diode 94 or 95 to the switchpairs of the selector unit, indicated at 96 and through the contacts 83back to the generator. The diodes 94 and 95 each permit current to flowonly in one direction, so that one coil 92 is energised only when theknob is rotated in one direction (to retract the bolt) and the othercoil is energised only when the knob is rotated in the other direction,to engage the bolt. The contacts 86, and the switch 91, are arranged inparallel in the circuit of the diode 94. The contacts 83 are arranged inthe circuit of the diode 95.

To release the bolt 71, the manual controls of the selector device areset to the combination which was chosen when the door was locked, andthe knob attached to 'the gear wheel 76 is rotated clockwise thusdriving the generator 77. Current is therefore supplied to the solenoidcoil 92 to draw the intermediate gear wheel 78 into its operativeposition and the bolt is retracted until the circuit is opened at thecontacts 86 by the roller 87 dropping into the notch 88, when the thirdgear wheels 82 are in mesh with the other gear wheels of the selectordeivce. The contacts 83 are closed by the initial movement of the bolt.

The combination can now be reset if desired, and the door is free toopen. By temporarily closing the switch 91 and again rotating the gearwheel 76 clockwise, the bolt 71 can be further retracted to againdisengage the third gear wheels 82, until the roller 87 drops into thenotch 89 and again opens the circuit. The driving members of theselector device can now be moved from their combination position, sothat the door cannot be relocked until the combination is restored. Tore-lock the door, the driving members are re-set to the combinationpositions and the gear wheel 76 is rotated clockwise, activating thegenerator to engage the intermediate gear wheel 78 by energisation ofthe solenoid coil 93, and so driving the bolt to the engaged position,when the contacts 83 open to break the electrical circuit due to theroller 84 dropping into the notch 85. The driving members of theselector device can now be again moved from their combination positions.

We claim:

1. A selector device for an electrical combination lock comprising, afirst and second multiposition electrical contact means, a drivecoupling means connected between said first and second multipositionelectrical contact means, a manual control means connected to said firstmultiposition electrical contact means for selecting at random a contactposition, means for disengaging said drive coupling means to permitmovement of said manual control independently of said secondmultiposition electrical contact means, and an electrical circuitcompleted through respective contacts on said first and secondmultiposition electrical contact means when said manual control is setat a given previously selected contact position.

2. A selector device according to claim 1, wherein an electricallycontrolled latch is provided to hold the drive coupling means in thedisengaged position, releasing means for the said latch being actuatedby completion of the electrical circuit.

3. A selector device according to claim 1, wherein the drive couplingmeans comprises a gear train includ ing gear members one of which ismovable out of engagement with another.

4. A selector device according to claim 1, wherein the drive couplingmeans is a clutch.

5. A selector device according to claim 3, wherein the gear traincomprises two coaxial gear wheels of equal size rotating respectivelywith the manual control and the driven member, and a third gear wheeladapted to mesh simultaneously with both of said coaxial gear wheels,said third gear wheel being movable in a direction normal to its axis todisengage it from said co-axial gear wheels.

6. A selector device according to claim 5, wherein the said third gearwheel is urged by spring means into engagement with the co-axialgearwheels, is movable out of engagement therewith by manual controlmeans, and is held in the disengaged position by the electricallycontrolled latch.

7. A selector device according to claim 1, wherein a plurality of manualcontrols are provided each connectible by a drive coupling means to adriven member, and the electrical circuit is completed only when all ofthe manual controls are in predetermined relative positions with respectto their associated driven members.

8. A selector device according to claim 2, wherein the electricalcircuit includes a normally open manually operated switch which must beclosed to complete said circuit.

9. A selector device according to claim 8, wherein an alarm deivce isprovided, means for operating the said alarm device being activated byclosure of the manually operated switch when the control and drivenmembers are not in their predetermined relative positions.

'10. A selector device according to claim 1 further comprising a bolt,manual operating means for said bolt, and means to prevent movement ofsaid bolt from a locking position, by said manual operating meanswherein said movement preventing means is operated to permit movement ofsaid bolt by a solenoid connected in said circuit for rendering saidmanual operating means operative.

11. A lock according to claim 10, wherein the manual operating means forthe bolt are arranged to drive an electric generator providing currentfor the electrical circuit.

12. An electrical combination lock comprising, a locking member meansfor inhibiting release of said locking member, an electrical circuit forcontrolling said release inhibiting means, contacts in said electricalcircuit, a selector device for selecting a combination of said contactsfor closing said electrical circuit and rendering said inhibiting meansinoperative, said selector deivce having at least two control groups,each of said control groups having a manual control settable to any oneof a plurality of positions, a driven member also movable to any one ofa plurality of positions, a first multiple position electrical contactmeans associated with said manual control, a second multiple positionelectrical contact means associated with said driven member, a drivecoupling means between said control and said driven member for simultaneously rotating said driven member and said control member, means fordisengaging said drive coupling means in each of said control groups topermit movement of said manual control independently of said drivenmember, actuating means for said disengaging means in each of saidcontrol groups, and means to render said release inhibiting meansoperative by any one of said actuating means, whereby said electricalcircuit is completed through contacts on said first and second multipleposition contact means when said manual controls of all of said controlgroups are in predetermined positions relative to said driven members ofsaid control groups.

References Cited UNITED STATES PATENTS 2/1935 Peterson 200-45 10/1959Neville, et al. 317-134

